How Do I Know What I Think Until I See What I Say?

Lately, I've been reading a lot of series YA books,* books that have two or three or four sequels, and I have to say that it hasn't been going so well. Usually, this is what happens: (1) I love the first book. It's awesome and original and the characters are great. (2) The second book is good. Maybe the idea isn't as good, or the characters seem a little stale or something. But it's still a pretty good book, and I'm looking forward to the next one. (3) I read book three and think "really"? and put it down halfway through after skimming to the end to find out who dies. For a while I wasn't sure why I was having that reaction. I mean, these are all different authors, writing about very different topics, so how was it possible that my reaction was pretty much the same each time? Was it ME? Could I be the problem?** Then I realized what was happening--it was the adults. I went back to confirm and, sure enough, in each of these different serie